1. Field of the Invention
The present invention relates to a method of manufacturing a flat panel display device, and more particularly, to a method of manufacturing a flat panel display device that is sealed by glass frits.
2. Description of the Related Technology
In general, flat panel display devices such as organic light emitting display devices and TFT-LCDs can be made thin and flexible, and thus, much research into such flat panel display devices is being conducted.
Organic light emitting display devices deteriorate as moisture penetrates therein, so that a sealing structure for preventing penetration of moisture is required.
Conventionally, a metal can or a glass substrate that is processed to a cap shape with a groove has been used as a sealing member. The metal can or glass substrate may contain a desiccant in powder form for absorbing moisture once it is sealed. Alternatively, a desiccant film may be attached to the sealing member using, e.g., a double-sided tape. In either case, the sealing member is combined with a substrate, on which a light emitting element is formed, using a UV curable organic sealant or a thermo-curable organic sealant.
When an organic sealant for combining a sealing member with a substrate is used, the resistance against pressure is small, the resistance to moisture penetration is lowered, thereby degrading a sealing effect.
Due to such problems as described above, glass frits with a high resistance to pressure and a good sealing characteristic has been suggested as a substitute for the organic sealant. In this case, a laser can be used to melt the glass frits and reduce a thermal effect on the organic light emitting element. However, in a mass-production process involving forming a plurality of light emitting devices on a single glass and cutting the glass into a plurality of devices, cut faces of the glass may deteriorate due to thermal stress generated by the radiation of the laser.
When melting the glass flit by laser, the temperature instantaneously rises to a high temperature of about 500-600° C., which thermally impacts the glass. Such a thermal impact leads to a deviation in stress between parts of the glass, so that cracks occur in an unintended direction when cutting the glass. As a result, protrusions, particles, etc., are generated on a cut face of the glass.